<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 100px;
            height: 100px;
            background: aqua;
            float: left;
        }
        .div1{
            transform: rotate(45deg);
        }
    </style>
</head>
<body>
<div class="div1"></div>
<div class="div2"></div>
</body>
</html>